1. Field of Invention
The present invention relates to mounting systems, in particular to methods and apparatus for mounting fasteners to hollow walls and ceilings.
2. Prior Art Fasteners
Most walls and ceilings of residential and commercial structures have a hollow cavity construction, i.e., there is a hollow space behind the wall. The wall comprises a sheet of material, typically between 1 and 2.54 cm thick, affixed to a suitable frame which includes wood or metal framing members (studs or joists). The framing members typically are spaced on 41 or 61 cm centers. The sheet material is sold under the trademark SHEETROCK by United States Gypsum Co., Chicago, and is known generically as drywall, wallboard, plasterboard, and gypsum board. Another less common wall and ceiling material with similar characteristics is plaster applied over a lath substrate. In the discussion below, the terms wall and ceiling are synonymous.
A variety of fasteners are commercially available for attaching, hanging, or securing objects such as pictures, mirrors, shelving, cabinetry, towel racks, handrails, and other objects to a wall at a location other than over the area where a framing member is located. Most of these fasteners can be divided into two general types: toggle and expansion.